Ph Meter - Sensor

[ffemt128]

Ph Meter - Sensor - Sample Size

Just a quick question and it's probably the obvious answer, but I'm going to ask anyway. I have the Phep5 meter. When doing an acid test the instructions recommend 10ml of wine. I have been using a 50 ml beaker since this enables the sensor to be covered completely by wine. The question now is;

Is it necessary to completely cover the sensor to get an accurate reading or is touching the wine sufficient?

I'm asking since with a magnetic stirrer, a larger beaker 100 ml would likely be necessary for use which would require a larger sample of wine be used and I would need to adjust my divisor for determining acid %.

 

[Runningwolf]

Doug I use a 40-80 ml beaker.

Add 5 ml of wine and enough distilled water to beaker to get a reading from your phep. maybe fill beaker 1 inch high. Your new multiplier after hitting 8.2 is .15

 

[Runningwolf]

Doug do yourself a favor and get a burett stand and clamp also to hold your ph meter. This is my set up..

And this is a close up of the clamp. I tried several till I found the perfect one.

 

[djrockinsteve]

You should cover all if not the majority of the probes for the best reading. I have several cups that are just like the medicine cups. The probes will be covered after you have added 4-5ml of sodium hydroxide. Your readings will start to be in range after this.

 

[ibglowin]

I use the $10 kit from More Wine and only 5 ml sample. I use the tilt and swirl technique at first. Tilt the vial to cover the entire probe with wine and swirl with one hand and add acid with the other (syringe). No mag stirrers, no burets, no ring stands.....

It takes a little coordination to get both hands doing something at the same time but it works well since it usually takes 5ml at least to get close to endpoint. By that critical time the container is more than full to cover the entire probe and you can then rotate it back to flat and even put it on your desktop to swirl.

This works extremely well for me since actual clear work area is in short supply in the winery!